Sudden Loss of Altitude Copter V4.0.6

Could really use some help with this log. I am unsettled as to just exactly what caused the sudden loss of altitude and crash. I keep going back to the current spike after the throttle input. The current load rapidly drops after spiking to near 70A. I’m leaning towards high impedance in the battery connector (XT90) to the drone, which led to the ESC’s browning out. Please, any suggestions greatly appreciated. Setup is an S900 with Cube Orange and Herelink. No loss of signal, or brownouts from what I am seeing. Am I overlooking something more important?

Motor 2 is commanded to maximum, or near maximum, indicating it’s losing thrust. Motor 1 has reduced output to compensate.

Current does go up and voltage down, but it’s not unreasonable to assume that’s just because of load.
Voltage and current never disappears like it would for a total connector failure. A connector would get very hot if it was giving trouble, and the pins would probably lose tension too.
Maybe the issue is motor desync or ESCs overheating??
Usually if a motor, prop or ESC fails the graph flatlines at the top since the flight controller commands absolute maximum available thrust - you dont have that effect.

Vibrations are high, especially Z vibrations. This wont be helping attitude control.

Needs some tuning, attitude control is poor

I think you’ll need to set

Use this spreadsheet to adjust your battery voltage settings slightly too

What motors, props and ESCs do you have? Is it all DJI?
You might need to set these, depending on which ESC you have:

Once you get everything sorted out, do a hover and some gentle flying around and share that log file.

Much thanks for the quick response. I wasn’t there when it was flown, but I am the one who set it all up. I flew it myself days prior with no issue. Vibes were within acceptable range and not as bad. Despite them being worse this time that still shouldnt account for sudden power loss, absent other obvious tall tell signs. I’ll look into your suggestions and follow up as soon as weather permits. Thanks again for your time.

By the way motors, ESCs’ and props all stock DJI.

There’s an issue I encountered with the DJI motors on a pair of S1000s. The steel stator is not properly glued to the motor bottom plate, and once unglued, it will start shifting cw/ccw depending on esc accelerate or break commands. Shifting is only limited by the coil wires, which start at first losing insulation and shorting on the aluminum bottom, then breaking off altogether. Although, sometimes the last stator shift at landing would press the broken copper wires together, yelding normal response at motor test commands and leaving one baffled.

Makes sense, I’ll check them out for this. Thanks!